Hong Ya Fu

A Review of Geometric Error Modeling and Error Detection for CNC Machine Tool

Error compensation can improve the accuracy of machine tools effectively. Among the error sources affecting the accuracy of CNC machine tool, geometric error is always set as a key performance criterion. This paper summarizes several methods of geometric error modeling and reviews the characteristics of different methods. Furthermore, available methods for measuring geometric errors have been reviewed also based on the advanced instruments. This work aims at enhancing the efficiency of error detection and give a perspective for the application of error compensation in the future.

A Review of Tensioner for Automated Fiber Placement

For automated fiber placement machine, tensioner is one of the important modules, which precisely generates and controls the tension of fibers.This paper performs a system analysis and synthesis of the key technologies of tensioner in recent years by summing up the development course of the tensioner. A new type of tensioner specially designed for fiber placment technology is presented. Experiments results prove the feasibility of the proposed mechanism and control algorithm. In addition, this paper also aims at giving a perspective in such area in the future.

A Framework of STEP-NC Manufacturing System Integrating CAD, CAPP, CAM and CNC

This paper outlines a conceptual framework of STEP-NC manufacturing system, which integrates the entire manufacturing process including CAD, CAPP, CAM and CNC, to make full use of the advantages of the new generation of data model. The STEP-NC manufacturing system consists of five parts and the STEP-NC standard is used to transport the complete product information. The intelligent CNC in this system can parse STEP-NC program directly so that no translation is needed and the part programs are reusable. Networked manufacturing can be realized by implementing this new framework of STEP-NC manufacturing system.

Modeling and Analysis of Key Geometric Error for Gravity Deformation of Heavy-Duty CNC Machine Tool

Gravity has huge impact on the accuracy of heavy-duty machine tools. To investigate errors caused by gravity, it is essential to figure out the most influential factor. This paper presents a geometric error modeling for heavy-duty CNC machine tools. Regarding a machine tool as a rigid multi-body system (MBS), the geometric error model has been established by utilizing kinematics chain and homogeneous transfer matrix (HTM). By analyzing the Jacobi matrix, the influence of all the geometric error parameters has been calculated to find out the key geometric error that affect the accuracy most. It is revealed that gravity of beam and tool affect the accuracy of the machine tool most through the ANSYS simulation. It supports a theoretical basis for the further research on error compensation of the key component of a machine tool.

Design of Ultrasonic Cutting Bench for Automatic Tape Laying Machine

Automatic tape laying is a widely-used fabricating process for fiber-reinforced composite materials in aerospace and aviation industry. To fulfill the tape laying process, it is necessary to cut the prepreg tape into designated shape accurately and promptly. In this paper, a scheme of ultrasonic cutting bench is put forward to investigate the parameters of ultrasonic cutting process. The functional requirements are analyzed and the key components of ultrasonic cutting bench, such as transverse feed mechanism of cutter, revolving gear of cutter, and mechanism for precision positioning of cutting depth, are presented in detail, which lays a solid foundation for future experimental research.

The Application of a Grating Tiling Device with Parallel Mechanism in an Inertial Confinement Fusion (ICF) System

The size of pulse compression gratings (PCG) is very big in the ICF system, so we obtained a large size grating by mechanically stitching small caliber gratings. And we design the splicing mechanism to be a 5-DOF Parallel Mechanism with macro/micro dual feed drive control to meet the requirements of large travel, high precision, high stability and 5-DOF of the grating tiling. The macro-moving part is designed to be the 5PTS-1PPS parallel mechanism, using the Feed Mechanism of ballscrew with Stepper Motor Drive.The micro-moving part is designed to be 5TSP-1PPS parallel mechanism, using the feed mechanism of Flexure Hinge with Piezoelectric Ceramic Actuator. We derived control algorithm of parallel mechanism by the method of the Kinematics of parallel mechanism. We analyzed the systematic error and put forward the error correction method in order to improve the positioning accuracy. At last, we designed an optical detecting system to evaluate the feasibility of this scheme, the positioning accuracy and the Stability of parallel Splicing structure. The results showed that the mechanism performance can meet the requirements of grating tiling work.

Secondary Development of Siemens CNC System for Large Grinding Machine

Form grinding is one of the most efficient processes for finish machining of gear wheels. This paper investigates the method of system development for wheel modification of involute cylindrical gear based on SINUMERIK 840D system and its OEM development package. The control software developed for form grinding is applied to dress form grinding wheel by using the numerical control dresser, and normal projection is adopted as the method to calculate the sectional shape of grinding wheel. The friendly interface of control software, edited by Visual Basic was developed to meet needs of users. Finally, personalized interface and processing methods are integrated and embedded in Siemens CNC system through Dynamic Link Library to implement parameterized automatic processing, which is more efficient in programming and machining.

A Review of Methodologies Used for Fault Diagnosis of Gearbox

A review of methods used for fault recognition of the rolling elements in gearbox, namely gear and bearing, is presented in this paper. The procedure of the fault recognition can be classified into three phases, which are data acquisition, data processing or important features extraction, and the fault mode detection. Many different methods have been developed in dealing with each phase, so that the arrangement of the entire process has different strategies. This paper summarizes some general used and recently popular developed methods of each phase, and makes comparison between them. This work also aims at giving a perspective in such area in the future, based on the known researches.

Low-Power Control and System Performance Research for Magnetic Flywheel

The magnetic flywheel is widely used in energy storage and spacecraft, and it needs to reduce the system’s power consumption effectively when designing the controller. Always, the magnetic bearing system’s performance depends on the tracking performance of the desired force signal. In order to balance the two goals between reducing magnetic system’s power consumption and guaranteeing its performance, a current power allocation way was proposed, and a static current optimization was given based on the way. According to the simulation and experimental results, this method can reduce the magnetic bearing system’s power consumption significantly and keep the tracking performance of force signal well on the same time.

Structural Vibration Control of the Magnetic Flywheel Based on GA-PID Neural Network

To overcome the difficult in modeling the mode theory for magnetic flywheel, by non-parametric frequency domain identification method for identification of system model, this paper select the PID neural network nonlinear intelligent control methods based on GA. Used a method based on iterative process to suppress the resonance, combined with zero-pole theory, this research designed a GA-based PID neural network identification controller to address the modal vibration suppression problems in the external rotor flywheel .The experiments for this paper proved the effectiveness of iterative process, and the controller can restrain the system mode vibration well.